Frequency Beam-scanning Antenna Research Articles

Circularly polarized beam-scanning antenna with eliminated open-stopband

In the paper, a circularly polarized (CP) frequency beam-scanning antenna based on photonic crystal (PC) is proposed, which possesses the characteristics of eliminating open-stopband (OSB). In the microwave field, the PC is typically constructed by embedding the air or metal column into the material. However, it is difficult for the PC with perfect magnetic conductor walls to accomplish the degeneracy of eigenmodes at the Γ point. Additionally, antennas based on the PC with perfect electric conductor walls exhibit a narrow scanning angle. The proposed unit based on 1D PC possesses perfect electric and magnetic conductor walls. The unit can not only eliminate OSB but also has a wide scanning range. In addition, the unit breaks into the original symmetrical field distributions of 1D PC. Based on the perturbation theory, leaky-wave slots can be designed to generate electromagnetic waves with the CP characteristics. And a CP antenna based on the unit is designed. The antenna can achieve a 70° beam-scanning within the entire operating band (7.6–9.2 GHz), and the variation of the realized gains is below 1.0 dBi around the broadside frequency. Simultaneously, the antenna is fabricated and measured. The measured results are in accordance with the simulation, which validates the success of the design.

A novel differential‐fed frequency beam scanning antenna with low sidelobe

AbstractIn this letter, a novel differential‐fed frequency beam‐scanning antenna is introduced. This differential structure is achieved by leveraging quasi‐Yagi radiating elements within a four‐layered geometry. Within this configuration, the element is excited by a pair of out‐of‐phase slow‐wave meander lines, through which differential signals are transmitted. These lines can be seamlessly integrated with other differential circuits. To ensure robust coupling, a broadside coupling structure is incorporated between adjacent layers. To corroborate theoretical insights, a prototype was constructed and tested. Measurements have shown that the primary beam can be scanned from −33.5° to +32.6° on a lateral plane, covering an operational frequency band of 9–11 GHz. Throughout this frequency range, a consistent peak gain of approximately 16.4 dBi is observed for the antenna.

A dual-band dual-polarized frequency beam-scanning antenna based on HMSIW and PC

A dual-band dual-polarized frequency beam-scanning (FBS) antenna based on half-mode substrate integrated waveguide (HMSIW) and photonic crystal (PC) is proposed. HMSIW can decrease the width of the substrate, and each eigenmode of PC has own unique electric-field distribution, which can be good for generating different polarization types. Therefore, the proposed antenna not only has a narrow substrate, but also has the characteristic of circularly polarized (CP) and linearly polarized (LP) radiation, which can be used for overcoming effectively the multipath fading and enhancing the channel capacity. For increasing the bandwidth of 3 dB axial ratio (AR), the slots on top surface are not perfectly symmetrical in the improved unit cell. The asymmetrical antenna based on the improved unit is manufactured and measured. The antenna can accomplish 33° scanning angle with the realized gains of 7.9–10.6 dBi in the CP working band (7.2 to 8.2 GHz), and can also achieve 24° beam-scanning for the LP radiation (8.8 to 9.6 GHz), whose realized gains are from 9.5 to 11.5 dBi. In addition, the experimental results are highly consistent with the simulated results, verifying that the design is feasible.

Circularly Polarized Millimeter Wave Frequency Beam Scanning Antenna Based on Aperture-Coupled Magneto-Electric Dipole

Based on the newly suggested wideband circularly polarized (CP) aperture-coupled magneto-electric dipole (MED), a millimeter-wave (mm-wave) frequency-scanned array (FSA) is proposed in this article. The MED is printed on two substrate layers. The electric dipole is two metal patches with perturbation structure, while the magnetic dipole is two rows of metal vias passing through the top substrate layer. The electric and magnetic dipoles, fed by a coupling slot, excite CP wave. By loading an arc-shaped vias row (AVR) at both ends of the magnetic dipole, the CP bandwidth with axial ratio (AR) less than 3 dB is extended to 40.9%. A new compact wideband transition from the rectangular waveguide (RWG) to the substrate integrated waveguide (SIW) is suggested as the feed structure for the CP FSA. A slow wave structure is etched on the ground of SIW to widen the beam scanning range. A 16-element array is designed and measured. The measured results show that the beam scanning range is 56° over 23–33 GHz band with a peak gain of 19.5 dBi. The CP mm-wave FSA has the advantages of wide scanning angle, low profile, and easy fabrication.

Design and Analysis of a Compact Frequency Beam-Scanning Antenna Based on Composite FHMSIW/SSPP Waveguide

In this letter, a novel compact frequency beam-scanning antenna (FBSA) using composite waveguide based on folded half-mode substrate integrated waveguide (FHMSIW) and spoof surface plasmon polaritons (SSPP) is proposed. The novel composite FHMSIW/SSPP waveguide with compact size and high field-confinement is initiated by embedding dual SSPP structures into the FHMSIW. Its transmission characteristic has flexible features from both the FHMSIW and SSPP. To excite the radiation mode from the composite slow-wave waveguide, a simple single-sided sinusoidal modulation method is designed and used. In this way, the common open stop-band problem around broadside is effectively eliminated, and the beam-scanning range of the antenna can be flexibly designed without changing the modulation structure. The presented scanning antenna owns a compact size and a simple feeding network. The experimental results indicate that the proposed FBSA can achieve continuous beam scanning from backward to forward in a wide scanning range of 60° within a bandwidth of 7.7–10.1 GHz. The stable unidirectional radiation patterns and appropriate gains are also realized in the entire operating frequency band.

A compact wide-angle frequency beam-scanning antenna using modulated composite waveguide based on half-mode substrate integrated waveguide and spoof surface plasmon polariton structure

In this paper, we present a novel frequency beam-scanning leaky-wave antenna (LWA) based on a composite half-mode substrate integrated waveguide/spoof surface plasmon polariton (HMSIW/SSPP) waveguide. The new composite HMSIW/SSPP waveguide is accomplished by embedding periodical symmetric subwavelength grooves on both copper surfaces of the HMSIW, which owns flexible transmission characteristics attributed to its features from both HMSIW and SSPP. The conversion of propagating slow-wave mode to radiation mode is devised by a double-sided symmetric sinusoidal modulation method with a π/2 displacement between the top- and bottom-surface. This double-sided modulation method not only offers a compact structure but also effectively eliminates the open stopband. A prototype of the proposed antenna is fabricated and measured to verify the predicted performance from simulation. Experimental results show that the proposed antenna achieves a continuous wide scanning range of 125° from backward to forward for lateral unidirectional radiation with an average peak gain level of 9.1 dBi from 6.3 to 9.7 GHz. And the compact antenna volume of 0.40 × 8.0 × 0.013 λ03 offers a well scanning rate (36.8°/GHz) and a very high gain value per unit volume (219 dBi/λ03).

Integrated Hybrid Antenna Based on Spoof Surface Plasmon Polaritons

In this paper, we proposed an integrated hybrid antenna based on spoof surface plasmon polaritons (SSPPs) which combines with omnidirectional antenna (ODA) and the frequency beam scanning antenna (FBSA). The ODA is fed by the SSPPs and the operating principle of FBSA is based on the higher-order modes of the SSPPs. The radiation mechanisms of the proposed integrated antenna are that the low-pass transmission modes of SSPPs are used to excite the ODA and the higher-order modes of SSPPs are utilized to generate the frequency beam scanning waves. That is to say, the SSPP design not only serves as the feeding structure for the ODA, but also acts as the radiating element for the FBSA. Simulated results show that the proposed integrated antenna achieves two impedance bandwidths. Within the operating bandwidth 2.32 GHz to 4.42 GHz, the proposed integrated antenna achieves omnidirectional radiation patterns, which enables the simultaneous use for wireless local area network (WLAN) and 5 G applications. Meanwhile, from 11.45 GHz to 25.5 GHz, the proposed integrated antenna acts as a wide-angle frequency beam scanning characteristic and can be used for planar integrated communication systems. Additionally, a prototype of the proposed integrated hybrid antenna is fabricated and tested. The measured results have a good agreement with the simulated ones.

Wide-Angle Frequency Beam Scanning Antenna Based on the Higher-Order Modes of Spoof Surface Plasmon Polariton

A wide-angle frequency beam scanning antenna based on spoof surface plasmon polaritons (SSPPs) is proposed for planar-integrated communication circuits. The SSPP-based antenna is constructed by hole arrays etched on the standard $50~\Omega $ coplanar waveguide, which can achieve ultrawide bandwidth and wide-angle beam scanning from backward direction to forward direction as the frequency changes. The radiation mechanisms of the SSPP-based antenna are based on the higher-order modes of the structure, which have been analyzed by the dispersion curves and electric field distributions. The overall width of the proposed SSPP-based antenna is only $0.95\lambda _{0}$ (with $\lambda _{0}$ being the wavelength of the lowest working frequency). The simulated results show that the proposed frequency beam scanning antenna achieves a wide scanning angle of 129° over a frequency range from 11.7 to 50 GHz (for $\vert S_{11}\vert dB) with an average gain level of 12.38 dBi. The good agreements between the simulated and measured results validate the proposed design.

Corrections to “Printed Frequency Beam-Scanning Antenna With Flat Gain and Low Sidelobe Levels”

Corrections to “Printed Frequency Beam-Scanning Antenna With Flat Gain and Low Sidelobe Levels”

Gain Enhancement for Circularly Polarized SIW Frequency Beam Scanning Antenna Using a Phase-Correcting Grating Cover

A planar circularly polarized (CP) frequency beam scanning Fabry-Perot resonator antenna (FPRA) with enhanced gain property is presented in this paper. The antenna consists of two layers. The CP substrate integrated waveguide (SIW) beam scanning leaky-wave antenna (LWA) is used as the feeding antenna. It provides good impedance matching and stable radiation pattern over the working band. Then, partially reflecting surface (PRS) layer is introduced to improve the gain property by using a single substrate with metal patches array printed on both top and bottom surfaces. After comparisons among four patch types, circular patch type is chosen. It is an ideal choice for CP antenna because of its completely symmetrical structure along φ-plane and gentler phase slope. Parameter analysis is made for better understanding of the working principle. Finally, the antenna is fabricated and measured for verification. It shows that the main beam scans from -38° to 28° within the operating frequency band from 9.1 to 14.6 GHz (or 47.8%). The 3-dB axial ratio (AR) bandwidth is from 10.2 to 13.5 GHz (or 28.7%). Maximum gain is 14.6 dBic, and 3-dB gain bandwidth is from 11 to 14 GHz (or 26.1%). Gain enhancement of about 3.3 ~ 6 dB is achieved, compared with the unloaded type. Due to the advantages of high gain, CP beam-scanning capability, and easy fabrication, this method is a good option to design antennas in wireless communication and radar systems.

A Circularly Polarized Frequency Beam-Scanning Antenna Fed by a Microstrip Spoof SPP Transmission Line

In this letter, a planar frequency beam-scanning antenna with a circularly polarized (CP) radiation property is proposed. The beam scans along the narrow side and in lateral plane of the antenna. The antenna consists of two layers: Eight periodic symmetrical patches are presented on the top layer as radiation elements to generate CP beam, while microstrip spoof surface plasmon polariton transmission line is used as the feeding line, which improves the beam scanning range. The antenna has been fabricated and measured to verify the theory analysis. Measured results indicate that the main beam scans from –5° to +37° in a lateral plane within the operating frequency band from 12 to 16.5 GHz, of which an excellent CP characteristic is also realized. The peak gain of the antenna is about 9.5 dBi over the whole band.

Millimeter-Wave Frequency Beam Scanning Array With a Phase Shifter Based on Substrate-Integrated-Waveguide

In this paper, a millimeter-wave multi-folded frequency-dependent progressive phase shifter based on substrate-integrated-waveguide (SIW) is proposed. The equations based on SIW TE10 mode characteristic are applied to design the parameters of the phase shifter. An end-fire magneto-electric dipole with wide beam width is employed as the radiating element. By combining the antenna element and the phase shifter together, a frequency beam scanning antenna array is proposed and analyzed, using mathematical calculation based on phase array theory. A prototype of the proposed array has been fabricated and measured. The theoretical calculation of radiation pattern of the array is verified by full-wave electromagnetic solver Ansys HFSS and measurement. The measurement results show that the array can achieve a wide scanning range from −18° to 32°, gain variation less than 2.9 dBi, and radiation efficiency around 50% from 57 to 63 GHz. With the advantages of simple and compact structure, wide beam scanning range, and low-cost processing, the proposed array would be a good candidate for millimeter-wave wireless communication.

Printed Frequency Beam-Scanning Antenna With Flat Gain and Low Sidelobe Levels

A frequency beam-scanning antenna with backfire-to-endfire beam-steering capability is proposed and investigated. This antenna is with printed planar structure that consists of a low-loss slow-wave printed meander line based on the even-mode bilateral broadside-coupled suspended microstrip line (BSML). The propagation properties of the meander-line unit and its principles for frequency-scanning applications are studied extensively. This printed antenna achieves the measured beam scanning of -27.5° to 46° with the frequency sensitivity of 43.24°/GHz and a maximum gain of 15.5 dBi. The antenna exhibits flat gain of more than 13 dBi in the whole frequency range from 8.9 to 10.6 GHz. The sidelobe levels are near 20 dB. The design flexibility of this kind of antenna is shown.